docs: def obj_to_string(obj):
      '''Render an object into a unicode string if possible'''
      if not obj:
          return None
      elif isinstance(obj, bytes):
          return obj.decode('utf-8')
      elif isinstance(obj, basestring):
          return obj
      elif is_lazy_string(obj):
          return obj.value
      elif hasattr(obj, '__html__'):
          return obj.__html__()
      else:
          return str(obj)